This invention relates to a bearing assembly and more particularly to elastomeric journal bearing assemblies which are adapted for marine propeller shafts. Elastomeric journal bearings have been found to be particularly suited for this purpose because of their exceptional ability to withstand the effects of corrosive fluids and to abrasion resulting from bits of foreign materials which are carried in suspension in the sea water or other liquids in which the shaft and journal bearing assembly operates. Such elastomeric journal bearing assemblies have been made and are still being made with rigid metallic non-corrosive support members but the materials are more expensive and the manufacturing costs are higher. A further advantage of the elastomeric journal bearings is that since they operate in a liquid medium they are self lubricated and therefore highly desirable for marine use as for the stern propeller shaft journals.
The present invention provides a novel method for making a new and improved elastomeric journal bearing utilizing a novel outer shell and inner shell wherein the integral assembly provides a plurality of circumferentially spaced radially inwardly extending projections that provides support for the shaft and a plurality of water wedges for lubricating purpose rather have the plural supports operate as squeeges which would wipe the lubricant off. The method employs a flat molding process that is combined with a winding process whereby a fiberglass reinforced rubber or elastomeric shell is further supported by a fiberglass reinforced plastic which provides a rigid outer housing for the inner flexible spaced supports. A unique advantage of the outer shell being fabricated from a fiberglass reinforced plastic made from an epoxy resin is that it permits the machining of the outer surface to a precise diameter and in the event that an error has been made in the dimensions of the outer surface, additional layers of fiberglass reinforced plastic can be molded back onto the outer shell by a simple winding process to increase it's dimensions to any desired size and thereafter store the assembly or machine the journal bearing assembly to a new dimension. This process is simple and can provide means for accurately sizing the outer diameter without the use of expensive molding processes. This process also permits the manufacture of numerous oversize journal bearing assemblies, storage of these asemblies and then machining of the assemblies to the precise dimension when needed. The materials used for the outer shell which is to be machined is an inexpensive rigid fiberglass reinforced plastic and of extreme importance is the fact that the bearing assembly will not swell and present start up problems inherent in other bearing assemblies.